The Skype app is already available on smartphones and tablets running Google Android, Apple iOS and Symbian, along with PCs, Macs and some connected TVs.

Skype said that following the beta on Windows Phone it has made a number of improvements to the service, including support for video calls in portrait mode, and better 'friend management' features, such the ability to send invites and block or unblock contacts.

"This is the first of many releases to come for Windows Phone, so stay tuned for even more capabilities in the future," said a press release.

"We believe in the great potential of the Windows Phone platform and will continue to invest over time to enable experiences unmatched by any other app in the market."